Wireless network emulators are being increasingly used for developing and
evaluating new solutions for Next Generation (NextG) wireless networks.
However, the reliability of the solutions tested on emulation platforms heavily
depends on the precision of the emulation process, model design, and parameter
settings. To address, obviate or minimize the impact of errors of emulation
models, in this work we apply the concept of Digital Twin (DT) to large-scale
wireless systems. Specifically, we demonstrate the use of Colosseum, the
world's largest wireless network emulator with hardware-in-the-loop, as a DT
for NextG experimental wireless research at scale. As proof of concept, we
leverage the Channel emulation scenario generator and Sounder Toolchain (CaST)
to create the DT of a publicly-available over-the-air indoor testbed for sub-6
GHz research, namely, Arena. Then, we validate the Colosseum DT through
experimental campaigns on emulated wireless environments, including scenarios
concerning cellular networks and jamming of Wi-Fi nodes, on both the real and
digital systems. Our experiments show that the DT is able to provide a faithful
representation of the real-world setup, obtaining an average accuracy of up to
92.5% in throughput and 80% in Signal to Interference plus Noise Ratio (SINR).Comment: 15 pages, 21 figures, 1 tabl